The present invention relates to a safety improvement technique in a projector type image display apparatus that is configured to display visual information by projecting it on a screen.
In a conventional liquid crystal projector that is configured to project an image on a screen in front of the projector, as there is a risk in that eyes of a speaker or other persons on the platform are stimulated by strong light when the persons enter into the path of the light projected from the projector to the screen and look toward the projector, such risk must be prevented by indicating precautions on the main body of the projector and so on.
Further, as described in Japanese Patent Laid-open No. 2000-305481 and Japanese Patent No. 2994469, there has been proposed a method for preventing such risk by providing detection means for detecting whether there is an object in a projection path and control means for controlling an amount of light from a projection lens, wherein light intensity from the projection lens is reduced when the object is detected.